Porcine circovirus-2 (PCV-2) was recently identified as an agent that has been consistently associated with post-weaning multisystemic wasting syndrome (PMWS) in swine populations in several parts of the world (Allan et al. 1998; Ellis et al., 1998). Isolates of PCV-2 obtained from infected pigs in several countries are virtually identical genetically, and are distinctly different from the PCV (CCL33, PCV-1) that was originally identified in the 1970's as a noncytopathic contaminant of porcine kidney (PK/15) cell line (Meehan et al. 1998; Tischer et al. 1974). Pigs with naturally acquired or experimentally induced PCV-2 infections present with progressive weight loss, tachypnea, dyspnea, and jaundice (Allan et al. 1998; Allan et al. 1999; Ellis et al. 1998; Ellis et al. 1999). Gross pathologic findings that have been directly associated with PCV-2 antigen include, lymphadenopathy, interstitial pneumonia, hepatitis and nephritis (Allan et al. 1998; Allan et al. 1999; Ellis et al. 1998; Ellis et al. 1999). PCV-2 has not heretofore been directly linked to abortion or lesions in fetal pigs. Thus, heretofore, it has not been proposed to address the issue of PCV-2-caused myocarditis, and/or abortion and/or intrauterine infection.